Numerous types of automatic vehicle wash equipment have been devised for washing vehicles automatically in the most efficient manner and with as few as employees as possible. Such vehicle wash equipment takes many different shapes, configurations, and constructions in an attempt to achieve the most efficient vehicle washing system. In many of these existing systems, the vehicle is driven into the wash station and is stopped whereupon the equipment moves with respect to the stationary vehicle. Some examples of such equipment for washing a stationary vehicle are shown in U.S. Pat. Nos. 3,102,545; 3,187,359; 3,368,572; 3,451,094;3,533,422; 3,545,459; 3,578,775; 3,604,434; 3,606,895; 3,645,282; 3,786,823; and 3,844,480. In other types of existing vehicle washing equipment the vehicle is moved through the wash station by a power driven conveyor or the like, and a plurality of spray nozzles apply pressurized fluid against the vehicle in combination with brushes that contact the vehicle as it moves through the wash station or bay. Examples of these types of vehicle washing equipment are shown in U.S. Pat. Nos. 3,391,700; 3,701,356; 3,421,169; and 3,557,808. A combination of the stationary and movable washing equipment is shown in U.S. Pat. No. 3,826,269.
Although some of these prior types of automatic vehicle washing eqiupment do clean the vehicle satisfactorily, in many instances some dirt will be left on the vehicle and other areas cleaned less satisfactorily than desired due to the distance of the spray nozzles from the vehicle. Also, many of these prior devices used rotating brushes or moving strips of fabric which contact the vehicle surface to remove the dirt. Even though these brushes and fabric strips are made from flexible material they still may scratch or mark the vehicle surface
It is known in the vehicle washing art that high pressure spray nozzles, if placed at a distance of from 8 to 12 inches from the vehicle surface with the nozzles being directed generally perpendicular toward the surface, provide an extremely efficient cleaning action without requiring any foreign material such as brushes or fabric strips contacting the vehicle surface. However, due to the differences in vehicle sizes and shapes that will enter an automatic wash facility the distance of the nozzles from the surface must vary considerably to insure that none of the nozzles contact the vehicles resulting in possible damage thereto.
Several types of vehicle wash equipment have attempted to provide a spray bar or spray nozzles which closely follow the contour of the vehicle in an attempt to maintain the nozzles within the preferred distance regardless of the vehicle profile. Examples of such equipment is shown in U.S. Pat. Nos. 3,410,284 and 3,533,422. The equipment of the first mentioned patent uses a horizontal vertically movable spray bar which is controlled by a photoelectric beam mounted directly on the vertically movable member. The beam attempts to detect the contour of the vehicle for raising and lowering the horizontal spray bar to a desired washing position. The bar is moved in accordance with the amount of beam intercepted by the vehicle. In the last mentioned patent, the vehicle is stationary and a U-shaped bar is moved horizontally along the vehicle. A vertically movable spray bar attempts to move in accordance with the contour of the vehicle by a pair of vertically spaced photoelectric sensors mounted on the bar. The sensors provide control signals for raising and lowering the spray bar in addition to controlling the horizontal movement thereof in an attempt to have the spray bar follow the contour of the stationary vehicle.
Photoelectric sensors also have been used in certain paint spraying operations in order for the spraying application to follow the contour of a part of a vehicle in which the spray pattern is dependent upon the profile of the vehicle or part thereof being sprayed. Examples of such paint spray control systems are shown in Pat. Nos. 3,593,308; 3,646,521; and 3,989,003.